Flavonoid Intake Linked to Reduced Risk of Type 2 Diabetes

In particular, a higher intake of tea, berries, and apples offered the most benefits.

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A diet high in flavonoid-rich foods, including berries, citrus fruits, tea, cocoa, onions—and yes, even wine—can reduce one’s risk of developing Type 2 diabetes.

In particular, a higher intake of tea, berries, and apples offered the most benefits.

The findings come from a study published in Nutrition & Diabetes on May 22. Researchers investigated the connection between flavonoid-rich foods and the onset of Type 2 diabetes within a large group of study participants in the UK.

Colorful Compounds

Flavonoids are chemical compounds found in fruits, vegetables, and flowers, often giving plants their colors. Unlike carbohydrates, proteins, and fats, metabolized in the stomach, flavonoids are broken down by gut bacteria and used by different parts of the body. They offer antioxidant, anti-inflammatory, anti-allergic, and anti-cancer properties.

There are six main subtypes of flavonoids: flavanones, flavones, flavan-3-ols, flavonols, anthocyanins, and isoflavones. Each offers different benefits.

Research has linked flavonoids to lower the risk of chronic diseases, including cardiovascular disease, and improved cognitive function.

Flavonoids Significantly Reduce Risks

In the UK study, researchers examined data from 113,097 individuals in the UK Biobank, a massive study involving more than 500,000 adults between 2006 and 2010. Two or more 24-hour dietary surveys assessed each participant’s flavonoid intake. The data were then analyzed using databases from the Department of Agriculture.

The research team studied 10 foods containing flavonoids: black and green tea, red wine, apples, berries, grapes, oranges, grapefruits, sweet peppers, onions, and dark chocolate. The average daily intake of flavonoids was 805.7 milligrams. Tea was the highest contributor of flavonoids, while peppers were the lowest. The overall intake, which equated to six servings of flavonoid-rich foods per day, was linked to a 28 percent lower risk of developing Type 2 diabetes compared to one serving of flavonoid-rich food per day.

Each additional serving of flavonoid-rich food reduced the risk of Type 2 diabetes by about 6 percent. Four servings of black or green tea per day were linked to a 21 percent lower risk. One serving of berries per day was linked to a 15 percent lower risk, and one serving of apples per day was linked to a 12 percent lower risk.

Different types of flavonoids were associated with varying incidents of Type 2 diabetes. A higher intake of anthocyanins, which are found in grapes, berries, and apples and give them their deep red, blue, and purple colors, was associated with a 19 percent lower risk; higher intake of flavan-3-ols, found in cocoa and tea, was associated with a 26 percent decreased risk; flavonols, found in cocoa, were associated with a 28 percent reduced risk; and proanthocyanidins, found in grape seeds and blueberries, were associated with a 27 percent decreased risk.

The findings suggest that a flavonoid-rich diet, especially one including tea, berries, and apples, affects how a person metabolizes sugar and can affect kidney and liver function. Eating more of these flavonoid-rich foods can help with weight management, further reducing Type 2 diabetes risk.

Diabetes Rampant in US

The study supports dietary guidelines recommending increasing fruit intake, especially berries and apples, to reduce Type 2 diabetes risk. According to the American Diabetes Association, 38.4 million Americans, or roughly 11.6 percent of the population, were diagnosed with diabetes in 2021. Just more than 1 million are diagnosed with diabetes each year, and more than 350,000 people aged 20 and younger live with the condition.

Additionally, 97.6 million Americans aged 18 and older have prediabetes, accounting for 38 percent of the population, according to the Centers for Disease Control and Prevention.